Abstract
Silicon nitride ceramics were fabricated by dry pressing of a raw α-Sι 3 N 4 powder with Y 2 O 3 -SiO 2 and Y 2 O 3 -Al 2 O 3 as sintering aids, following by gas-pressured sintering at a temperature of 2123 K for 2 h under a nitrogen gas pressure of 1.0 MPa with Si 3 N 4 /BN packing powder. Subsequently, these specimens were heat-treated at a temperature up to 2223 K for 8 h under a nitrogen gas pressure of 1.0 MPa without any packing powder. Mass loss, density, oxygen content and thermal conductivity of the specimens before and after the post-sintering heat-treatment were measured. Due to the heat-treatment, the reduction of oxygen content, via the reaction of Si 3 N 4 and SiO 2 , without decrease of relative density was found to be effective in improving thermal conductivity of the Si 3 N 4 ceramics sintered with Y 2 O 3 -SiO 2 additives. The effect of post-sintering heat-treatment was not significant for the Si 3 N 4 specimen sintered with Y 2 O 3 -Al 2 O 3 additives due to formation of SiAlON. Thermal conductivity of one of the former specimens reached 84 W/m.K at room temperature.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
